Why doesn't Physics Forums allow people to post "new theories" and other speculative ideas, or try to disprove well-established theories like relativity?

We believe such discussions detract from our mission of helping people who want to understand science as practiced by professional scientists, as described in our [URL='http://www.physicsforums.com/showthread.php?t=414380']Global Guidelines[/URL]. We have chosen to focus on these people, rather than on those who want freewheeling speculation. There are other places on the internet that cater to such speculation.

One of our major "markets" is high-school and university students who use us to help them understand the material that they are studying. We don't want to give them a mistaken impression of the current "state of the art" in professional science by encouraging excessive speculation, cranks and crackpots.

But isn't speculation an important part of the scientific process?

Yes, indeed! It's so important that we think it should be left to the professionals, at graduate-school level and beyond. Before one can productively think "outside the box", one has to know where the walls of the box are in the first place. Professional scientists already have ways of discussing their ideas with colleagues. We do not aim to become one of those ways. It is not part of our mission to aid in the advancement of science, only in the understanding of science.

What about people who do have professional-level knowledge of physics, maybe even with a Ph.D., but aren't affiliated with a university or other institute? Shouldn't they have a place to discuss their ideas with others?

We tried to cater to people like these, with a moderated Independent Research forum. It failed. See below for a history of this attempt.[B]

What if a well-established physicist wanted to post his new theory here and discuss it before publishing it?

We would politely explain our policy and tell him that he is very welcome to discuss his theory here after publishing it.

What about students who come up with tentative theories as part of their learning process?

Some students try to post such theories as a way of filling the gaps in their current understanding of science, with the intention of learning from having them shot down. We think it is more effective to pose focused questions about current theories, to address those gaps.

Has PF at least tried allowing speculative discussions?

Yes, we did, during our earlier years. People spent a lot of time arguing with crackpots and others who didn't want to give up their ideas even in the face of experimental evidence.

Sometime in 2003 or earlier, we created a Theory Development forum and moved all speculative threads there. This allowed such discussions to continue, while keeping the other forums focused on mainstream science.

After a while, we decided that the Theory Development forum wasted too much of our and other posters' resources in arguing with crackpots and cranks, and in moderating threads that got out of control, and that it detracted from our main mission. In July 2005, we closed Theory Development and replaced it with a moderated Independent Research forum:

(The forum was originally going to be named Outside the Mainstream, but it was changed to Independent Research just before its actual startup.) Briefly, new threads had to start with an opening post similar to the abstract of a scientific journal article, and meet certain standards to help screen out obvious crackpot-type stuff. If the opening post was approved, discussion would proceed normally. The intent was to allow discussion of serious alternative theories and speculations that don't contradict well-established science.

It turned out that very few opening posts made it through the initial moderation process. The ones that did, tended either to produce little actual discussion, or to degenerate into a sort of "blog" containing only posts from the original poster, adding to his ideas or revising them. In June 2011, we decided that the Independent Research forum was not productive enough to be worth the time and effort needed to moderate it, and so we closed it: